Gunner: Have a Thief and Skull at Level 15, and pass the "Sunset Kind Of Guy" bill.

Lady Samurai: Have a Valkyire and Archer at Level 30.

Magic Knight: Have a Warrior or Valkyrie, and Skull or Witch at Level 30, and pass a bill in the Dark Senate.

Masked Hero: Have a Thief and Warrior at Level 25, and pass the "Hero Of The Future" bill.

Ninja: Have a Thief and Skull at Level 30, and pass a bill in the Dark Senate.

Onmyo Monk: Have a Sorcerer and Ninja at Level 30, and pass the "Feng Shui Specialist" bill.

Professor: Have a Healer and Onmyo Monk at Level 20, and pass a bill in the Dark Senate.

Samurai: Have an Archer and Valkyrie at Level 30, and pass a bill in the Dark Senate.

Sorcerer: Have a Skull and Witch at Level 15, and pass the "Curse Loving Girl" bill.

Star Mage: Have a total level of 50 between all of your Red, Blue, and Green Witches.

Star Skull: Have a total level of 50 between all of your Red, Blue, and Green Skulls.

X-Dimension unlockables

Successfully complete the indicated percentage of X-Dimension stages to unlock the corresponding bonus:

Candidate Ribbon: 20%

Celebration Ball: 60%

Gold Senator Badge: 100%

Lucky Headband: 40%

Victory Daruma: 80%

Legendary Tree relationships

Unlock the Legendary Tree bill in Episode 4, and pass it in the Senate to get a new evil symbol that allows you to setup a series of relationships for the symbol's leader. You also use it to unlock epilogues and give new effects to the leader, which is done by gaining relationships. The effects usually disappears when a member is removed from the symbol's area of effect. Successfully complete the following tasks to make the relationships permanent:

Training Wing (Left): Commando Pirates on Floors 51 and higher on the Innocent Boost or Item Growth paths (does not appear on Turn 2). Note: On the first set of floors, take either gate on Floor 5 and then the other gate on Floor 10 (Item gate).

Treasure Ship (Body): Peachboy Pirates on Floors 51 and higher on the Treasure Path (does not appear on Turn 2).

Duplicating items

In Disgaea 3: Absence Of Justice, when you went to the Item World and your bags and storage were both full, the item you had been exploring would be lost (due to there being no room in your bag or storage for it to be returned. In Disgaea 4: A Promise Unforgotten, the programmers attempted to correct this by sending the item in question to the Rosen Queen (store) where you can then buy it once you have made enough room. If you go to either the weapon or armor store, you can "try on" the item. If you "try on" the item, and buy it from that option (instead of directly buying it), then leave the store, when you return to the store the item will be there again, allowing you to repeat the process, and in effect duplicating the item (including specialists) as many times as desired. If you buy the item directly, or save or load your game, the item will no longer be available for purchase. Basically, fill your inventory and storage, then do one of the following things: go to the Item World and complete a 10th (or 20th, 30th, etc.) level, bringing you back out of the item (make sure you pick up an item to fill the hole made when entering); or reverse pirate an item to the same purpose; or create a new character (human or monster), equip them with a weapon, then reincarnate them to the other class (if monster, incarnate human and if human, incarnate monster). This will remove your equipped weapon, and because you can no longer wear it due to class change, it triggers the glitch to send it to the store.

Trophies

Successfully complete one of the following tasks to get a trophy:

Unanimously Elected (Platinum): Complete all other trophies. You have obtained all the trophies.

Additionally, there are 50 secret trophies:

Biggus Stickus (Gold): Inflict 10,000,000,000 damage.

Evildoer of the Year (Gold): Unlock all Evil Symbols.

Items Roadshow (Gold): Collect all items (excluding grades). Now aim for completing all the grades, too!

Pimp My Ship (Silver): Collect all of the Pirate Ship parts.

Intelligence Director (Silver): All ranks of all job and monster classes can be created through Character Creation.

Special Stalker (Silver): Watch all of the special skills.

X-tra-Dimension-al Conquistador (Silver): Clear all of the X-Dimension maps.